mid-15c., "small or poor knife," of uncertain origin probably related to Danish spyd, Old Norse spjot "spear," German Spiess "spear, lance"). Meaning "spade" is from 1660s; sense of "short or stumpy person or thing" is from 1680s; that of "potato" is first recorded 1845 in New Zealand English.

spud

noun

A potato

[1845+; origin unknown; perhaps related to the fact that in British dialect use spud means ''a weeding instrument'' and in US dialect it means ''a spade,'' hence potatoes would be something spudded or dug; a relation has been seen between the fact that potatoes are also the nickname of men named Murphy, or indeed of any Irishman]

The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D.Copyright (C) 2007 by HarperCollins Publishers.Cite This Source